feat: add types

Takes the types from [@types/protocol-buffers-schema](https://www.npmjs.com/package/@types/protocol-buffers-schema)
and adds them to this module.

It swaps node `Buffer`s for `Uint8Array`s in the interfaces because
this module doesn't use any `Buffer` features that aren't available
on `Uint8Array`s which makes it a bit kinder to the browser.

index.d.ts

@@ -0,0 +1,10 @@
+
+import { Schema } from "./types";
+declare namespace parse {
+    function parse(buffer: string | Uint8Array): Schema;
+    function stringify(schema: Schema): string;
+}
+
+declare function parse(buffer: string | Uint8Array): Schema;
+
+export = parse;

parse.d.ts

@@ -0,0 +1,9 @@
+import { Schema } from "./types";
+declare namespace parse {
+    function parse(buffer: string | Uint8Array): Schema;
+    function stringify(schema: Schema): string;
+}
+
+declare function parse(buffer: string | Uint8Array): Schema;
+
+export = parse;

tokenize.d.ts

@@ -0,0 +1,5 @@
+import { Schema } from "./types";
+
+declare function tokenize(schema: Schema): string[];
+
+export = tokenize;

types.d.ts

@@ -0,0 +1,82 @@
+export interface Option {
+  [key: string]: string | boolean;
+}
+
+export interface Options {
+  [key: string]: string | boolean | Option | Option[];
+}
+
+export interface Enum {
+  name: string;
+  values: {
+      [key: string]: {
+          value: number;
+          options: Options;
+      };
+  };
+  options: Options;
+}
+
+export interface FieldOptions {
+  [key: string]: string;
+}
+
+export interface Field {
+  name: string;
+  type: string;
+  tag: number;
+  map: {
+      from: string;
+      to: string;
+  };
+  oneof: null | string;
+  required: boolean;
+  repeated: boolean;
+  options: FieldOptions;
+}
+
+export interface Message {
+  name: string;
+  enums: Enum[];
+  extends: Extend[];
+  extensions: Extension[];
+  messages: Message[];
+  options: Options;
+  fields: Field[];
+}
+
+export interface Extend {
+  name: string;
+  message: Message;
+}
+
+export interface Extension {
+  from: number;
+  to: number;
+}
+
+export interface Service {
+  name: string;
+  methods: Method[];
+  options: Options;
+}
+
+export interface Method {
+  name: string;
+  input_type: string;
+  output_type: string;
+  client_streaming: boolean;
+  server_streaming: boolean;
+  options: Options;
+}
+
+export interface Schema {
+  syntax: number;
+  package: null | string;
+  imports: string[];
+  enums: Enum[];
+  messages: Message[];
+  options: Options;
+  extends: Extend[];
+  services?: Service[];
+}